1. Field of the Invention
The present invention relates to a technique for removing foreign matter present at a scanning point of an original in an original conveying apparatus.
2. Description of the Related Art
Conventionally, there is known an ADF (Auto Document Feeder) that conveys, in an image forming apparatus such as a printer or a digital multifunction peripheral, an original such that the original can be scanned by a CIS (Contact Image Sensor), which is a scanning unit of the image forming apparatus.
As a technique for detecting presence or absence of foreign matter on an original glass of the CIS, there is known a technique for arranging a member having a high reflectance on the ADF side facing the original glass, detecting the foreign matter by detecting a value of a reflectance different from that of the member on the basis of an output of a scanning unit that receives reflected light of the member, and notifying a user of the foreign matter.
However, in the technique, a result of the detection of the foreign matter is only notified to the user. When scanning of an original is not stopped after the notification, an image failure occurs in an output image. When the scanning of the original is stopped, since a copy or scan operation is suspended, waste of resources or time is caused.
There is also known a technique for removing foreign matter on a scanning point on an original glass by always closely attaching an original to the scanning point (JP-A-2003-321143). However, a conveying angle suitable for scanning the original and a conveying angle suitable for removing the foreign matter are different.